Start slow. Start with low pressure (your pump DOES include a gauge, I hope...), and short duration, with frequent breaks, and limited cumulative time per session. Take a day off every now and then. Work your way up to longer sessions over time.

Be Safe, Be Careful, & Enjoy!
As many pumpers will tell U...start slow and be clear about the instructional use. I use one from time to time.
If U have any problems...do check the advise of some LPSG members as U are doing now...hope you get the dick girth you want but don't damage what U already have.Roma was built in a day!
Whopper-lee:wink: